Tuatara: Volume 21, Issues 1 and 2 (New Zealand Albatrosses and Petrels: an Identification Guide)
28. Black-Capped Petrel — (Pterodroma externa cervicalis) — Plate 12
28. Black-Capped Petrel
(Pterodroma externa cervicalis)
Field Characters: 96/43. A large gadfly petrel with black cap, grey upperparts, mostly white underparts and wedge-shaped tail. A conspicuous white nape collar contrasts sharply with the black cap and grey mantle. Forehead and face white. An obvious dark open ‘M’ marking extends from wing tip to wing tip. Underparts white, except for an inconspicuous black leading margin extending from the page 40 carpal joint diagonally for a short distance over the white inner underwing coverts.
Bill black, feet bi-coloured.
Differs from Juan Fernandez Petrel (54) by its conspicuous white nape collar, black cap and grey (not black) tail.
Flight similar to other gadfly petrels, but with steeper and higher arcing, interspersed with occasional slow wingbeats. Does not follow ships.
Summer breeder on the Kermadec Islands (Macauley and, until recently, Raoul Island) and disperses into Central Pacific.